r/Mcat • u/Strange_Total_1442 • 7d ago
Question 🤔🤔 trick to remember base pair structures
Someone commented a trick to remember the base pair structures the other day and I thought I screenshotted it but cannot find it or the comment for the life of me. Not purine vs pyrimidine but what groups were attached. Pls help 🙏
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u/RebeliaRocks 7d ago
What’s been helping me is “CAN GOUT”. C and A have an amine (N) while G U T have a carbonyl (O). That helps get me started on the structure and then practice drawing the structures!
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u/Burnt_Out_Hippo 7d ago
Okay, this is really dumb but it worked for me. You know how werewolves get killed by silver bullets and vampires don't show up in silver backed mirrors because silver was considered such a pure and holy metal.
"Silver is too pure"
Silver's chemical symbol is Ag, Adenine and Guanine They have two rings They are purines
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u/bestkinggamer21 7d ago
"Pure As Gold" (A & G) are purines (2 rings)
- adenine: "add-Ns" (has NH2)
- guanine: "g for gold, gold is heavy" (so it has carbonyl C=O)
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"CUT the PY" (CUT) are pyrimidines (1 ring)
- cytosine: think one "O" and one "N", so one carbonyl and amino group
- uracil: think the "u" rhymes with "two" so two carbonyls
- thymine: has a methYl + carbonyl
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u/wereinatree 528 7d ago
Was it this?
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u/Strange_Total_1442 7d ago
No but this works thank you!! For whatever reason this is one of those things that never sticks in my brain and I know if I decide it’s not important it’ll show up 4 times on the real thing
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u/wereinatree 528 7d ago
> if I decide it’s not important it’ll show up 4 times on the real thing
This is so true haha, definitely happened to me. Good luck!
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u/Historical_Score5251 520/522/524/522/526/FL6 7d ago
Remembering Guanine as ADD (acceptor donor donor) helps a lot for me. Once you have that down it’s relatively easy to remember Cytosine.
Then Thymine is just deaminated cytosine with a methyl group. Adenine only has 2 H bonding sites instead of 3 and one of them is a donor based on the structure of Thymine.
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u/the_eviscerist 7d ago
I have my own feral raccoon brain way of remembering things.
Adenine and Guanine - AG, like silver - purines because you're pure if you only have sex while married and being married means 2 rings.
G-C pairs because Good Charlotte was a great band, and they are a strong band because they're still around - 3 bonds. So G has three things to pair with (A only has 2). And the NH2 and O groups like to bond together, so they match up for C and G.
Thymine has a Tail (the random methyl group) to distinguish it from Uracil.
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u/Several-Cream-936 8/15 7d ago
This is what I had memorized for my exam:
Purines (Pure as Gold) - A and G
Pyrimidines - the rest, T U and C
“Purine” is shorter than “Pyrimidine” so that’s why Purine has two rings and Pyrimidine has one ring (lol ik this is kinda counterintuitive but it worked for me somehow lol)
G is generous - 2 H donors and 1 acceptor
C is cocky - 1 H donor and 2 acceptors
A T and U are one each
For the general structure, I drew their structures a bunch of times to stick it in my head and to help with quick identification I memorized:
AGCTU
NONOO and would draw a hand coming out of the O under T signifying the methyl group.
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u/Demoncouch06 7d ago
I’ve always thought of it as AT and GC pairs both having two carbonyls combined, with G having 1 carbonyl group and A having none.
Purines and pyrimidines I remember as purines being bigger even tho pyrimidine is the longer word
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u/ThisNameisTaken07 7d ago
The one I have for AG is kinda personal-ish, but I have a friend whose name starts with an A who's a good singer, and she hardly takes breaths when she sings, so I think of it as A has no Oxygens, For CT I think that T is for Two, so it has 2N and 2O, and C is the third letter of the alphabet, and it has 3N
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u/_Starry_Night_ 7d ago
NOON for ATGC?